Vehicle control system with adaptive wheel angle correction

ABSTRACT

A control system of a vehicle includes an image sensor and a control having an image processor. The image sensor is disposed at the vehicle and has a field of view exterior and forward of the vehicle. The image processor is operable to process image data captured by the image sensor to determine a curvature of a road being traveled by the vehicle. Responsive at least in part to processing by the image processor of captured image data, the control is operable to determine tangents at locations along the determined curvature. Responsive to determination of the tangents, the control is operable generate an output to adjust the vehicle steering to guide the vehicle in a direction that generally corresponds to determined tangents at respective locations of the vehicle&#39;s path of travel along the curvature of the road.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the filing benefits of U.S. provisionalapplication Ser. No. 61/977,929, filed Apr. 10, 2014, which is herebyincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to a vehicle vision system for avehicle and, more particularly, to a vehicle vision system that utilizesone or more cameras at a vehicle.

BACKGROUND OF THE INVENTION

Use of imaging sensors in vehicle imaging systems is common and known.

Examples of such known systems are described in U.S. Pat. Nos.5,949,331; 5,670,935 and/or 5,550,677, which are hereby incorporatedherein by reference in their entireties.

SUMMARY OF THE INVENTION

The present invention provides a vision system or imaging system for avehicle that utilizes one or more cameras (preferably one or more CMOScameras) to capture image data representative of images exterior of thevehicle, and provides an adaptive steering or wheel angle correction toguide or maintain the vehicle within its lane boundaries as the vehicleis driven along a road.

The vision system or control system of the present invention uses asensor disposed at a vehicle and having a field of view exterior of thevehicle (such as an image sensor or camera having a field of viewforward of the vehicle), whereby a processor is operable to process datacaptured by the sensor to determine a curvature of the road beingtraveled by the vehicle. The processor is operable to determine tangentsat locations along the determined curvature and, responsive to adetermination of the tangents, the processor generates an output to avehicle control. The control, responsive to the output, is operable toadjust the vehicle steering to guide the vehicle in a direction thatgenerally corresponds to a determined tangent at respective locations ofthe vehicle along the curved road. The processor may generate the outputat least in part responsive to at least one of a vehicle yaw rate, avehicle velocity and a vehicle lateral acceleration. The control mayadjust the vehicle steering to have a front wheel of the vehiclegenerally parallel to a tangent of the road at the end of the curvature,whereby the vehicle is traveling substantially straight along the roadfollowing the road curvature.

These and other objects, advantages, purposes and features of thepresent invention will become apparent upon review of the followingspecification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a vehicle with a vision system thatincorporates cameras in accordance with the present invention;

FIG. 2 is a schematic of a vehicle driving direction along a tangent ofa curve in accordance with the present invention;

FIG. 3 is a block diagram of the adaptive wheel angle correction systemof the present invention; and

FIG. 4 is a block diagram of an adaptive wheel angle correctionalgorithm used by the system of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A vehicle vision system and/or driver assist system and/or objectdetection system and/or alert system and/or control system operates tocapture images exterior of the vehicle and may process the capturedimage data to display images and to detect objects at or near thevehicle and in the predicted path of the vehicle, such as to assist adriver of the vehicle in maneuvering the vehicle in a rearward orforward direction. The vision system includes an image processor orimage processing system that is operable to receive image data from oneor more cameras and provide an output to a display device for displayingimages representative of the captured image data. Optionally, the visionsystem may provide a top down or bird's eye or surround view display andmay provide a displayed image that is representative of the subjectvehicle, and optionally with the displayed image being customized to atleast partially correspond to the actual subject vehicle.

Referring now to the drawings and the illustrative embodiments depictedtherein, a vehicle 10 includes an imaging system or vision system 12that includes at least one exterior facing imaging sensor or camera,such as a rearward facing imaging sensor or camera 14 a (and the systemmay optionally include multiple exterior facing imaging sensors orcameras, such as a forwardly facing camera 14 b at the front (or at thewindshield) of the vehicle, and a sidewardly/rearwardly facing camera 14c, 14 d at respective sides of the vehicle), which captures imagesexterior of the vehicle, with the camera having a lens for focusingimages at or onto an imaging array or imaging plane or imager of thecamera (FIG. 1). Optionally, a forward viewing camera may be disposed atthe windshield of the vehicle and view through the windshield andforward of the vehicle, such as for a machine vision system (such as fortraffic sign recognition, headlamp control, pedestrian detection,collision avoidance, lane marker detection and/or the like). The visionsystem 12 includes a control or electronic control unit (ECU) orprocessor 18 that is operable to process image data captured by thecamera or cameras and may detect objects or the like and/or providedisplayed images at a display device 16 for viewing by the driver of thevehicle (although shown in FIG. 1 as being part of or incorporated in orat an interior rearview mirror assembly 20 of the vehicle, the controland/or the display device may be disposed elsewhere at or in thevehicle). The data transfer or signal communication from the camera tothe ECU may comprise any suitable data or communication link, such as avehicle network bus or the like of the equipped vehicle.

The system of the present invention determines a lane of travel ahead ofthe vehicle (such as be determining lane markers or the like) andadjusts the steering of the vehicle to guide or steer the vehicle alonga curvature of the lane. The lane keeping algorithm of the presentinvention applies a correction (such as a torque to the steeringmechanism) to keep the vehicle within the determined lane boundaries.After the correction has been applied (to guide the vehicle along thecurvature), there is a residual wheel angle (even after the vehicle hastraversed through the curved path and is at a straight or straightersection of road after the curved section of road), which causes thevehicle to cross the center line of the lane. The present inventionprovides an algorithm that determines a wheel angle correction such thatthe wheel angle is corrected such that the vehicle is parallel to atangent of the road curvature (such that, at the end of the maneuver thevehicle has zero lateral acceleration, and zero lateral velocity). Forexample, FIG. 2 shows the tangents at points along a curved section ofroad.

As shown in FIG. 3, the system may receive signals pertaining to vehiclevelocity, yaw rate and lateral acceleration, and may determine laneparameters, such as curvature, a curvature derivative heading andposition with respect to the vehicle. The signals are conditioned and/orfiltered and/or validated and then fed to the algorithm, whichdetermines the degree of adjustment or steering to apply to the vehicleto guide or steer the vehicle along the curve and within the laneboundaries. The system may determine the end of a lateral maneuver sothe algorithm can determine when to stop the processing. The lanekeeping controller, responsive to processing of the algorithm, isoperable to adjust the steering or apply a torque to adjust or steer thevehicle.

As shown in FIG. 4, the algorithm compares the lane curvature andheading estimation with the vehicle position estimation to determine alateral error and a vehicle wheel angle estimation (to steer the vehiclealong the curve in the road).

The system and algorithm may determine the lane markers or boundariesand lane curvature and relative vehicle position via any suitable means.For example, the system may determine the lane markers or boundaries andlane curvature and relative vehicle position via image processing ofimage data captured by a forward viewing camera of the vehicle (andoptionally one or more other cameras or sensors of the vehicle, such asa rearward viewing camera and/or sideward viewing cameras or the like).The system may determine the curvature of the lane in which the vehicleis traveling by utilizing aspects of the systems described in U.S.patent application Ser. No. 14/663,502, filed Mar. 20, 2015 (AttorneyDocket MAGO4 P-2478), which is hereby incorporated herein by referencein its entirety.

The camera or sensor may comprise any suitable camera or sensor.Optionally, the camera may comprise a “smart camera” that includes theimaging sensor array and associated circuitry and image processingcircuitry and electrical connectors and the like as part of a cameramodule, such as by utilizing aspects of the vision systems described inInternational Publication Nos. WO 2013/081984 and/or WO 2013/081985,which are hereby incorporated herein by reference in their entireties.

The system includes an image processor operable to process image datacaptured by the camera or cameras, such as for detecting objects orother vehicles or pedestrians or the like in the field of view of one ormore of the cameras. For example, the image processor may comprise anEyeQ2 or EyeQ3 image processing chip available from Mobileye VisionTechnologies Ltd. of Jerusalem, Israel, and may include object detectionsoftware (such as the types described in U.S. Pat. Nos. 7,855,755;7,720,580 and/or 7,038,577, which are hereby incorporated herein byreference in their entireties), and may analyze image data to detectvehicles and/or other objects. Responsive to such image processing, andwhen an object or other vehicle is detected, the system may generate analert to the driver of the vehicle and/or may generate an overlay at thedisplayed image to highlight or enhance display of the detected objector vehicle, in order to enhance the driver's awareness of the detectedobject or vehicle or hazardous condition during a driving maneuver ofthe equipped vehicle.

The vehicle may include any type of sensor or sensors, such as imagingsensors or radar sensors or lidar sensors or ladar sensors or ultrasonicsensors or the like. The imaging sensor or camera may capture image datafor image processing and may comprise any suitable camera or sensingdevice, such as, for example, a two dimensional array of a plurality ofphotosensor elements arranged in at least 640 columns and 480 rows (atleast a 640×480 imaging array, such as a megapixel imaging array or thelike), with a respective lens focusing images onto respective portionsof the array. The photosensor array may comprise a plurality ofphotosensor elements arranged in a photosensor array having rows andcolumns. Preferably, the imaging array has at least 300,000 photosensorelements or pixels, more preferably at least 500,000 photosensorelements or pixels and more preferably at least 1 million photosensorelements or pixels. The imaging array may capture color image data, suchas via spectral filtering at the array, such as via an RGB (red, greenand blue) filter or via a red/red complement filter or such as via anRCC (red, clear, clear) filter or the like. The logic and controlcircuit of the imaging sensor may function in any known manner, and theimage processing and algorithmic processing may comprise any suitablemeans for processing the images and/or image data.

For example, the vision system and/or processing and/or camera and/orcircuitry may utilize aspects described in U.S. Pat. Nos. 7,005,974;5,760,962; 5,877,897; 5,796,094; 5,949,331; 6,222,447; 6,302,545;6,396,397; 6,498,620; 6,523,964; 6,611,202; 6,201,642; 6,690,268;6,717,610; 6,757,109; 6,802,617; 6,806,452; 6,822,563; 6,891,563;6,946,978; 7,859,565; 5,550,677; 5,670,935; 6,636,258; 7,145,519;7,161,616; 7,230,640; 7,248,283; 7,295,229; 7,301,466; 7,592,928;7,881,496; 7,720,580; 7,038,577; 6,882,287; 5,929,786 and/or 5,786,772,and/or International Publication Nos. WO 2011/028686; WO 2010/099416; WO2012/061567; WO 2012/068331; WO 2012/075250; WO 2012/103193; WO2012/0116043; WO 2012/0145313; WO 2012/0145501; WO 2012/145818; WO2012/145822; WO 201 2/1 581 67; WO 2012/075250; WO 2012/0116043; WO2012/0145501; WO 2012/154919; WO 2013/019707; WO 2013/016409; WO2013/019795; WO 2013/067083; WO 2013/070539; WO 2013/043661; WO2013/048994; WO 2013/063014, WO 2013/081984; WO 2013/081985; WO2013/074604; WO 2013/086249; WO 2013/103548; WO 2013/109869; WO2013/123161; WO 2013/126715; WO 2013/043661 and/or WO 2013/158592, whichare all hereby incorporated herein by reference in their entireties. Thesystem may communicate with other communication systems via any suitablemeans, such as by utilizing aspects of the systems described inInternational Publication Nos. WO/2010/144900; WO 2013/043661 and/or WO2013/081985, and/or U.S. Publication No. US-2012-0062743, which arehereby incorporated herein by reference in their entireties.

The imaging device and control and image processor and any associatedillumination source, if applicable, may comprise any suitablecomponents, and may utilize aspects of the cameras and vision systemsdescribed in U.S. Pat. Nos. 5,550,677; 5,877,897; 6,498,620; 5,670,935;5,796,094; 6,396,397; 6,806,452; 6,690,268; 7,005,974; 7,937,667;7,123,168; 7,004,606; 6,946,978; 7,038,577; 6,353,392; 6,320,176;6,313,454 and/or 6,824,281, and/or International Publication Nos. WO2010/099416; WO 2011/028686 and/or WO 2013/016409, and/or U.S. Pat.Publication No. US 2010-0020170, which are all hereby incorporatedherein by reference in their entireties. The camera or cameras maycomprise any suitable cameras or imaging sensors or camera modules, andmay utilize aspects of the cameras or sensors described in U.S.Publication No. US-2009-0244361 and/or U.S. Pat. Nos. 8,542,451;7,965,336 and/or 7,480,149, which are hereby incorporated herein byreference in their entireties. The imaging array sensor may comprise anysuitable sensor, and may utilize various imaging sensors or imagingarray sensors or cameras or the like, such as a CMOS imaging arraysensor, a CCD sensor or other sensors or the like, such as the typesdescribed in U.S. Pat. Nos. 5,550,677; 5,670,935; 5,760,962; 5,715,093;5,877,897; 6,922,292; 6,757,109; 6,717,610; 6,590,719; 6,201,642;6,498,620; 5,796,094; 6,097,023; 6,320,176; 6,559,435; 6,831,261;6,806,452; 6,396,397; 6,822,563; 6,946,978; 7,339,149; 7,038,577;7,004,606; 7,720,580 and/or 7,965,336, and/or International PublicationNos. WO/2009/036176 and/or WO/2009/046268, which are all herebyincorporated herein by reference in their entireties.

The camera module and circuit chip or board and imaging sensor may beimplemented and operated in connection with various vehicularvision-based systems, and/or may be operable utilizing the principles ofsuch other vehicular systems, such as a vehicle headlamp control system,such as the type disclosed in U.S. Pat. Nos. 5,796,094; 6,097,023;6,320,176; 6,559,435; 6,831,261; 7,004,606; 7,339,149 and/or 7,526,103,which are all hereby incorporated herein by reference in theirentireties, a rain sensor, such as the types disclosed in commonlyassigned U.S. Pat. Nos. 6,353,392; 6,313,454; 6,320,176 and/or7,480,149, which are hereby incorporated herein by reference in theirentireties, a vehicle vision system, such as a forwardly, sidewardly orrearwardly directed vehicle vision system utilizing principles disclosedin U.S. Pat. Nos. 5,550,677; 5,670,935; 5,760,962; 5,877,897; 5,949,331;6,222,447; 6,302,545; 6,396,397; 6,498,620; 6,523,964; 6,611,202;6,201,642; 6,690,268; 6,717,610; 6,757,109; 6,802,617; 6,806,452;6,822,563; 6,891,563; 6,946,978 and/or 7,859,565, which are all herebyincorporated herein by reference in their entireties, a trailer hitchingaid or tow check system, such as the type disclosed in U.S. Pat. No.7,005,974, which is hereby incorporated herein by reference in itsentirety, a reverse or sideward imaging system, such as for a lanechange assistance system or lane departure warning system or for a blindspot or object detection system, such as imaging or detection systems ofthe types disclosed in U.S. Pat. Nos. 7,881,496; 7,720,580; 7,038,577;5,929,786 and/or 5,786,772, which are hereby incorporated herein byreference in their entireties, a video device for internal cabinsurveillance and/or video telephone function, such as disclosed in U.S.Pat. Nos. 5,760,962; 5,877,897; 6,690,268 and/or 7,370,983, and/or U.S.Publication No. US-2006-0050018, which are hereby incorporated herein byreference in their entireties, a traffic sign recognition system, asystem for determining a distance to a leading or trailing vehicle orobject, such as a system utilizing the principles disclosed in U.S. Pat.Nos. 6,396,397 and/or 7,123,168, which are hereby incorporated herein byreference in their entireties, and/or the like.

Optionally, the circuit board or chip may include circuitry for theimaging array sensor and or other electronic accessories or features,such as by utilizing compass-on-a-chip or EC driver-on-a-chip technologyand aspects such as described in U.S. Pat. Nos. 7,255,451 and/or7,480,149, and/or U.S. Publication No. US-2006-0061008, which are herebyincorporated herein by reference in their entireties.

Optionally, the vision system may include a display for displayingimages captured by one or more of the imaging sensors for viewing by thedriver of the vehicle while the driver is normally operating thevehicle. Optionally, for example, the vision system may include a videodisplay device disposed at or in the interior rearview mirror assemblyof the vehicle, such as by utilizing aspects of the video mirror displaysystems described in U.S. Pat. No. 6,690,268 and/or U.S. Publication No.US-2012-0162427, which are hereby incorporated herein by reference intheir entireties. The video mirror display may comprise any suitabledevices and systems and optionally may utilize aspects of the compassdisplay systems described in U.S. Pat. Nos. 7,370,983; 7,329,013;7,308,341; 7,289,037; 7,249,860; 7,004,593; 4,546,551; 5,699,044;4,953,305; 5,576,687; 5,632,092; 5,677,851; 5,708,410; 5,737,226;5,802,727; 5,878,370; 6,087,953; 6,173,508; 6,222,460; 6,513,252 and/or6,642,851, and/or European patent application, published Oct. 11, 2000under Publication No. EP 0 1043566, and/or U.S. Publication No.US-2006-0061008, which are all hereby incorporated herein by referencein their entireties. Optionally, the video mirror display screen ordevice may be operable to display images captured by a rearward viewingcamera of the vehicle during a reversing maneuver of the vehicle (suchas responsive to the vehicle gear actuator being placed in a reversegear position or the like) to assist the driver in backing up thevehicle, and optionally may be operable to display the compass headingor directional heading character or icon when the vehicle is notundertaking a reversing maneuver, such as when the vehicle is beingdriven in a forward direction along a road (such as by utilizing aspectsof the display system described in International Publication No. WO2012/051500, which is hereby incorporated herein by reference in itsentirety).

Optionally, the vision system (utilizing the forward facing camera and arearward facing camera and other cameras disposed at the vehicle withexterior fields of view) may be part of or may provide a display of atop-down view or birds-eye view system of the vehicle or a surround viewat the vehicle, such as by utilizing aspects of the vision systemsdescribed in International Publication Nos. WO 2010/099416; WO2011/028686; WO 2012/075250; WO 2013/019795; WO 2012/075250; WO2012/145822; WO 2013/081985; WO 2013/086249 and/or WO 2013/109869,and/or U.S. Publication No. US-2012-0162427, which are herebyincorporated herein by reference in their entireties.

Optionally, a video mirror display may be disposed rearward of andbehind the reflective element assembly and may comprise a display suchas the types disclosed in U.S. Pat. Nos. 5,530,240; 6,329,925;7,855,755; 7,626,749; 7,581,859; 7,446,650; 7,370,983; 7,338,177;7,274,501; 7,255,451; 7,195,381; 7,184,190; 5,668,663; 5,724,187 and/or6,690,268, and/or in U.S. Publication Nos. US-2006-0061008 and/orUS-2006-0050018, which are all hereby incorporated herein by referencein their entireties. The display is viewable through the reflectiveelement when the display is activated to display information. Thedisplay element may be any type of display element, such as a vacuumfluorescent (VF) display element, a light emitting diode (LED) displayelement, such as an organic light emitting diode (OLED) or an inorganiclight emitting diode, an electroluminescent (EL) display element, aliquid crystal display (LCD) element, a video screen display element orbacklit thin film transistor (TFT) display element or the like, and maybe operable to display various information (as discrete characters,icons or the like, or in a multi-pixel manner) to the driver of thevehicle, such as passenger side inflatable restraint (PSIR) information,tire pressure status, and/or the like. The mirror assembly and/ordisplay may utilize aspects described in U.S. Pat. Nos. 7,184,190;7,255,451; 7,446,924 and/or 7,338,177, which are all hereby incorporatedherein by reference in their entireties. The thicknesses and materialsof the coatings on the substrates of the reflective element may beselected to provide a desired color or tint to the mirror reflectiveelement, such as a blue colored reflector, such as is known in the artand such as described in U.S. Pat. Nos. 5,910,854; 6,420,036 and/or7,274,501, which are hereby incorporated herein by reference in theirentireties.

Optionally, the display or displays and any associated user inputs maybe associated with various accessories or systems, such as, for example,a tire pressure monitoring system or a passenger air bag status or agarage door opening system or a telematics system or any other accessoryor system of the mirror assembly or of the vehicle or of an accessorymodule or console of the vehicle, such as an accessory module or consoleof the types described in U.S. Pat. Nos. 7,289,037; 6,877,888;6,824,281; 6,690,268; 6,672,744; 6,386,742 and/or 6,124,886, and/or U.S.Publication No. US-2006-0050018, which are hereby incorporated herein byreference in their entireties.

Changes and modifications in the specifically described embodiments canbe carried out without departing from the principles of the invention,which is intended to be limited only by the scope of the appendedclaims, as interpreted according to the principles of patent lawincluding the doctrine of equivalents.

1. A control system of a vehicle, said control system comprising: animage sensor disposed at a vehicle and having a field of view exteriorand forward of the vehicle; a control comprising an image processoroperable to process image data captured by said image sensor todetermine a curvature of a road being traveled by the vehicle; wherein,responsive at least in part to processing by said image processor ofcaptured image data, said control is operable to determine tangents atlocations along the determined curvature; and wherein, responsive todetermination of the tangents, said control is operable generate anoutput to adjust a vehicle steering to guide the vehicle in a directionthat generally corresponds to determined tangents at respectivelocations of the vehicle's path of travel along the curvature of theroad.
 2. The control system of claim 1, wherein said control, responsiveat least in part to processing by said image processor of captured imagedata, determines an end of the curvature of the road where the roadstraightens.
 3. The control system of claim 2, wherein said control,responsive to a determination that the vehicle is at the end of thecurvature of the road, adjusts a wheel angle of the vehicle such thatthe vehicle is parallel to a tangent of the road at the end of thecurvature of the road.
 4. The control system of claim 3, wherein, whenthe wheel angle is adjusted to be parallel to the tangent of the road atthe end of the curvature of the road, the vehicle has generally zerolateral acceleration and generally zero lateral velocity.
 5. The controlsystem of claim 1, wherein said control generates the output at least inpart responsive to at least one of a vehicle yaw rate, a vehiclevelocity and a vehicle lateral acceleration.
 6. The control system ofclaim 1, wherein said control adjusts a wheel angle of the vehicle suchthat the vehicle is parallel to a tangent of the road curvature.
 7. Thecontrol system of claim 6, wherein, at the end of the controlledmaneuver along the curved road, the vehicle has generally zero lateralacceleration and generally zero lateral velocity.
 8. The control systemof claim 1, wherein said control comprises an algorithm that adjusts awheel angle of a front wheel the vehicle such that the vehicle frontwheel is generally parallel to the tangent of the road curvature.
 9. Thecontrol system of claim 1, wherein said control, at least in partresponsive to signals indicative of (i) vehicle velocity, (ii) vehicleyaw rate and (iii) vehicle lateral acceleration, determines laneparameters relative to the vehicle.
 10. The control system of claim 9,wherein said determined lane parameters comprise a curvature derivativeheading and position relative to the vehicle.
 11. The control system ofclaim 9, wherein said control receives the signals and wherein analgorithm of said control determines the degree of steering adjustmentto apply to the vehicle steering to guide the vehicle along the curveand within the lane boundaries.
 12. The control system of claim 11,wherein said control determines an end of a turning maneuver so thealgorithm can determine when to stop the processing of the signals. 13.A control system of a vehicle, said control system comprising: an imagesensor disposed at a vehicle and having a field of view exterior andforward of the vehicle; a control comprising an image processor operableto process image data captured by said image sensor to determine acurvature of a road being traveled by the vehicle; wherein, responsiveat least in part to processing by said image processor of captured imagedata, said control is operable to determine tangents at locations alongthe determined curvature; wherein said control generates the output atleast in part responsive to at least one of a vehicle yaw rate, avehicle velocity and a vehicle lateral acceleration; wherein saidcontrol, responsive at least in part to processing by said imageprocessor of captured image data, determines an end of the curvature ofthe road where the road straightens; wherein, responsive todetermination of the tangents, said control is operable generate anoutput to adjust a vehicle steering to guide the vehicle in a directionthat generally corresponds to determined tangents at respectivelocations of the vehicle's path of travel along the curvature of theroad; and wherein said control, responsive to a determination that thevehicle is at the end of the curvature of the road, adjusts a wheelangle of the vehicle such that the vehicle is parallel to a tangent ofthe road at the end of the curvature of the road.
 14. The control systemof claim 13, wherein, when the wheel angle is adjusted to be parallel tothe tangent of the road at the end of the curvature of the road, thevehicle has generally zero lateral acceleration and generally zerolateral velocity.
 15. The control system of claim 13, wherein saidcontrol comprises an algorithm that adjusts a wheel angle of a frontwheel the vehicle such that the vehicle front wheel is generallyparallel to the tangent of the road curvature.
 16. The control system ofclaim 13, wherein said control, at least in part responsive to signalsindicative of (i) vehicle velocity, (ii) vehicle yaw rate and (iii)vehicle lateral acceleration, determines lane parameters relative to thevehicle, and wherein said determined lane parameters comprise acurvature derivative heading and position relative to the vehicle. 17.The control system of claim 16, wherein said control receives thesignals and wherein an algorithm of said control determines the degreeof steering adjustment to apply to the vehicle steering to guide thevehicle along the curve and within the lane boundaries, and wherein saidcontrol determines an end of a turning maneuver so the algorithm candetermine when to stop the processing of the signals.
 18. A controlsystem of a vehicle, said control system comprising: an image sensordisposed at a vehicle and having a field of view exterior and forward ofthe vehicle; a control comprising an image processor operable to processimage data captured by said image sensor to determine a curvature of aroad being traveled by the vehicle; wherein, responsive at least in partto processing by said image processor of captured image data, saidcontrol is operable to determine tangents at locations along thedetermined curvature; wherein said control, responsive at least in partto processing by said image processor of captured image data, determinesan end of the curvature of the road where the road straightens; wherein,responsive to determination of the tangents, said control is operablegenerate an output to adjust a vehicle steering to guide the vehicle ina direction that generally corresponds to determined tangents atrespective locations of the vehicle's path of travel along the curvatureof the road; wherein said control comprises an algorithm that adjusts awheel angle of a front wheel the vehicle such that the vehicle frontwheel is generally parallel to the tangent of the road curvature; andwherein said control, responsive to a determination that the vehicle isat the end of the curvature of the road, adjusts a wheel angle of thevehicle such that the vehicle is parallel to a tangent of the road atthe end of the curvature of the road.
 19. The control system of claim18, wherein said control, at least in part responsive to signalsindicative of (i) vehicle velocity, (ii) vehicle yaw rate and (iii)vehicle lateral acceleration, determines lane parameters relative to thevehicle, and wherein said determined lane parameters comprise acurvature derivative heading and position relative to the vehicle. 20.The control system of claim 19, wherein said control receives thesignals and wherein the algorithm of said control determines the degreeof steering adjustment to apply to the vehicle steering to guide thevehicle along the curve and within the lane boundaries, and wherein saidcontrol determines an end of a turning maneuver so the algorithm candetermine when to stop the processing of the signals.